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Obesity-associated podocyte injury increases in parallel with inflammatory responses. Resveratrol, as an anti-inflammatory and antioxidative agent, has been proven to be effective in obesity. The purpose of the present study was to investigate the function of resveratrol in the early stages of podocyte injury in ovariectomized rats fed a high-fat diet (HFD). The 3-month-old female Wistar rats were randomly divided into four groups: Sham operation with a standard diet; sham operation with a HFD; ovariectomy with a HFD (O+H); and ovariectomy plus HFD treatment with resveratrol (40 mg/kg/day) (O+H+R). Following 12 weeks, the weights of the rats were measured and serum was obtained to measure the levels of 17β-estradiol (E2), serum lipids, serum creatinine, fasting blood glucose (FBG) and insulin. Periodic acid-schiff staining was used to detect renal pathological changes. Meanwhile, the expression of the podocyte-associated proteins nephrin and Wilms' tumor-1 was investigated using immunohistochemical staining, and the levels of tumor necrosis factor-α, interleukin-6 and monocyte chemotactic protein-1 in renal tissues were determined using western blotting. Compared with the O+H group, resveratrol significantly reduced the body weight, serum levels of total cholesterol, low-density lipoprotein cholesterol, FBG and insulin resistance, and increased the levels of E2 in obese rats with an ovariectomy combined with an HFD (P<0.05). Compared with the O+H group, although the O+H+R group had no significant changes in renal pathology, the changes in the levels of podocyte-associated proteins and inflammatory markers were significantly reversed (P<0.05). These results suggest that resveratrol may attenuate early podocyte injury by improving lipid metabolism and insulin sensitivity, and subsequently inhibiting inflammatory responses in obese rats induced by an ovariectomy with a HFD. [ABSTRACT FROM AUTHOR]

Diabetic nephropathy (DN) is by far the most common cause of end‑stage renal disease (ESRD) in industrial countries, accounting for ~45% of all new ESRD cases in the United States. Grape seed proanthocyanidin extracts (GSPE) are powerful antioxidants, with an antioxidant ability 50‑fold greater than that of vitamin E and 20‑fold greater than that of vitamin C. The present study investigated whether GSPE can protect against streptozotocin (STZ)‑induced DN and aimed to elucidate a possible mechanism. Male Sprague Dawley rats were randomly divided into three groups: Control group (N), diabetes mellitus group (DM) injected with 40 mg/kg STZ, and the GSPE treatment group (intragastric administration of 250 mg/kg/day GSPE for 16 weeks after diabetes was induced in the rats). Blood and kidney samples were collected after treatment. The renal pathological changes were determined with periodic acid‑Schiff (PAS) staining, while the protein expression levels of glucose‑regulated protein 78 (GRP78), phosphorylated‑extracellular signal‑regulated kinase (p‑ERK) and Caspase‑12 were determined by western blotting and immunohistochemical staining. Apoptosis was determined with a terminal deoxynucleotidyl transferase dUTP nick‑end labeling (TUNEL) assay. Compared with the DM group, the GSPE group had no significant changes in the blood urea nitrogen (BUN) level and serum creatinine (Scr) level, but showed a significant decline in the renal index (RI) level and 24‑h urinary albumin level (P<0.05). The histopathology results indicated very little pathological damage in the GSPE group. Compared with the DM group, the GSPE group had a significantly reduced number of TUNEL‑positive cells (P<0.05), and the GSPE group had an obvious reduction in the protein expression of GRP78, p‑ERK, and Caspase‑12 (P<0.05). In this study, the results indicated that GSPE can protect renal function and attenuate endoplasmic reticulum stress‑induced apoptosis via the Caspase‑12 pathway in STZ‑induced DN. [ABSTRACT FROM AUTHOR]